Impact of 21st century climate change on the Baltic Sea fish community and fisheries

The Baltic Sea is a large brackish semienclosed sea whose species-poor fish community supports important commercial and recreational fisheries. Both the fish species and the fisheries are strongly affected by climate variations. These climatic effects and the underlying mechanisms are briefly reviewed. We then use recent regional – scale climate – ocean modelling results to consider how climate change during this century will affect the fish community of the Baltic and fisheries management. Expected climate changes in northern Europe will likely affect both the temperature and salinity of the Baltic, causing it to become warmer and fresher. As an estuarine ecosystem with large horizontal and vertical salinity gradients, biodiversity will be particularly sensitive to changes in salinity which can be expected as a consequence of altered precipitation patterns. Marine-tolerant species will be disadvantaged and their distributions will partially contract from the Baltic Sea; habitats of freshwater species will likely expand. Although some new species can be expected to immigrate because of an expected increase in sea temperature, only a few of these species will be able to successfully colonize the Baltic because of its low salinity. Fishing fleets which presently target marine species (e.g. cod, herring, sprat, plaice, sole) in the Baltic will likely have to relocate to more marine areas or switch to other species which tolerate decreasing salinities. Fishery management thresholds that trigger reductions in fishing quotas or fishery closures to conserve local populations (e.g. cod, salmon) will have to be reassessed as the ecological basis on which existing thresholds have been established changes, and new thresholds will have to be developed for immigrant species. The Baltic situation illustrates some of the uncertainties and complexities associated with forecasting how fish populations, communities and industries dependent on an estuarine ecosystem might respond to future climate change.     

Killickia (Lamiaceae): a new genus from KwaZulu-Natal, South Africa

The genus Killickia is described to accommodate the South African endemic species formerly placed in Micromeria sect. Hesperothymus . Morphological data, as well as results from unpublished phylogenetic studies support its separation from the genera Micromeria and Clinopodium . A new species Killickia lutea Bräuchler is described and three new combinations are made. Killickia is characterised as comprising solitary- or few-flowered cymes, a campanulate to subcampanulate (obconical) calyx with similar teeth, a corolla tube with two pubescent ridges and nutlets with scattered minute hairs. A thickened marginal vein in the leaves as typical for Micromeria is absent. As currently understood all species are restricted to the Drakensberg mountains and KwaZulu-Natal Midlands in eastern South Africa. A key to the species, brief notes on anatomy and ecology are provided.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 575–586.     

Methane emission from Siberian arctic polygonal tundra: eddy covariance measurements and modeling

Eddy covariance measurements of methane flux were carried out in an arctic tundra landscape in the central Lena River Delta at 72°N. The measurements covered the seasonal course of mid‐summer to early winter in 2003 and early spring to mid‐summer in 2004, including the periods of spring thaw and autumnal freeze back. The study site is characterized by very cold and deep permafrost and a continental climate with a mean annual air temperature of ?14.7 °C. The surface is characterized by wet polygonal tundra, with a micro‐relief consisting of raised moderately dry sites, depressed wet sites, polygonal ponds, and lakes. We found relatively low fluxes of typically 30 mg CH₄ m^?2 day^?1 during mid‐summer and identified soil temperature and near‐surface atmospheric turbulence as the factors controlling methane emission. The influence of atmospheric turbulence was attributed to the high coverage of open water surfaces in the tundra. The soil thaw depth and water table position were found to have no clear effect on methane fluxes. The excess emission during spring thaw was estimated to be about 3% of the total flux measured during June–October. Winter emissions were modeled based on the functional relationships found in the measured data. The annual methane emission was estimated to be 3.15 g m^?2. This is low compared with values reported for similar ecosystems. Reason for this were thought to be the very low permafrost temperature in the study region, the sandy soil texture and low bio‐availability of nutrients in the soils, and the high surface coverage of moist to dry micro‐sites. The methane emission accounted for about 14% of the annual ecosystem carbon balance. Considering the global warming potential of methane, the methane emission turned the tundra into an effective greenhouse gas source.     

Characterization of Sulphate Uptake in Anacystis nidulans

Sulphate uptake in the blue-green alga Anacystis nidulans appears based upon an active mechanism with a Km of 0.75 μM and V_max of 0.7 pmol/min × 10⁶ cells. Sulphate uptake is competitively inhibited by thiosulphate and sulphite. The sulphate uptake has a pH optimum at 8 and a temperature optimum at 40°C. By increasing the extracellular sulphate concentration from 0.1 to 10 μM the sulphate pool in Anacystis was altered from 8.3, 10^?5M to 5.9, 10^?4M.     

Modulation of Normal Human Melanocyte Dendricity by Growth-Promoting Agents

Dendrite formation and extension, which comprise a characteristic morphology of human normal melanocytes in the skin, represent one of the functional activities of melanocytes, the ability to transfer melanosomes into neighboring keratinocytes. However, the morphology of the melanocyte in vitro is usually quite different from that observed in vivo. it is probably due to the hyperproliferative condition of the melanocytes in culture. No studies have ever compared the effects of a single factor on both dendricity and proliferation at the same time. Therefore, we have compared the effects of six growth-promoting agents commonly used for melanocyte cultures on dendrite formation and proliferation. The addition of agents that increase the intracellular levels of cyclic adenosine monophosphate (cAMP)—dibutyryl cyclic adenosine monophosphate (db cAMP; 1 mM) or isobutylmethyl xanthine (IBMX; 0.1 mM)—had a strong effect on dendrite formation and a negative effect on proliferation. This was especially true with db cAMP. In the presence of 2% or 5% of heat-inactivated fetal bovine serum (FBS), dendrite formation was significantly increased as was proliferation. The number of dendrites was decreased in the culture with 12-o-tetradecanoylphorbol-13-acetate (TPA), but cell growth was slightly increased. With human recombinant basic fibroblast growth factor (bFGF) (0.5, 1.0 ng/ml) in the presence of bovine pituitary extract (BPE) (60 μg/ml), cell growth was increased. With 2 ng/ml of bFGF, however, a strong inhibitory effect on proliferation was observed. However, dendrite formation was constant at all concentrations of bFGF tested (0.5, 1.0 or 2.0 ng/ml) with BPE (30 or 60 μg/ml). In this study, we have demonstrated that dendrite formation was suppressed by the reagents that stimulate melanocyte proliferation, and vice versa, with the only exception being heat-inactivated FBS. Both dendrite formation and proliferation were induced by the heat-inactivated FBS. This approach is crucial to the development of an adequate culture system for proliferation and/or dendrite formation of normal human melanocytes. It is necessary to keep these aspects in mind as we further investigate the biology of melanocytes, especially the cell-to-cell interactions between melanocytes and keratinocytes, involved in melanogenesis and melanin pigmentation in vivo. This study also provides practical and important information for a future reconstitutive skin system composed of melanocytes, keratinocytes, and fibroblasts in a single culture medium.     

SPERMIOGENESIS AND SPERMATOPHORE IN TELEMA TENELLA SIMON (ARANEAE: TELEMIDAE)—AN ULTRASTRUCTURAL STUDY

The spermatophore of the cave-spider Telema tenella is elaborated in the vas deferens. It has the shape of a long inverted gutter with two rows of digitations and spermatozoa piled up inside. The spermatozoon possesses a 9 + 3 axoneme, retracted in the cytoplasm to form from 4 to 4.5 peripheral whorls; the elongated nucleus and its acrosomal rod make 1.5 whorl. The spermatozoa keep the main part of their cytoplasm. The spermatophore is inserted in the male palp, then transferred to the female during coition. With the exception of this family, all other male Araneae transfer free spermatozoa during coition.     

Garden Warbler Sylvia borin migration in sub-Saharan West Africa: phenology and body mass changes

The Garden Warbler is a classic subject for the study of Palaearctic–African bird migration strategies. Most studies have considered the situation close to the breeding areas, while the African and especially the sub‐Saharan part of the species’ migration have received comparatively little attention. Here we use autumn and spring ringing data from Nigeria and The Gambia to study the movements and energetics of the species in West Africa during the non‐breeding season. The first Garden Warblers arrive south of the desert around the beginning of September, roughly at the same time as the median date for their passage through the Baltic Sea region and c. 3 weeks before their median passage date through southern Italy. In the Nigerian Sahel savannahs, where, owing to the rainy season and its associated increase in food availability, many more Garden Warblers stop over in autumn than in the dry spring, the median date of passage is 1 October. The body mass on arrival south of the desert is normally only a few grams more than the lean body mass (LBM; 15 g) – with a mean of 16.6 g (sd = ±1.8 g) in The Gambia and 17.4 g (sd = ±1.8 g) in the Nigerian Sahel. After resting and refuelling in the Sahel, Sudan and Guinea‐type savannahs the Garden Warblers depart during November–December for wintering areas further south. Before leaving, they again increase their body mass, with an average fuel load of c. 20%, and often more than 50% relative to LBM. Some of the birds passing through Nigeria probably spend midwinter around the Congo Basin. During spring they return northwards to the Guinea savannah zone in April and fuel‐up there for the trans‐Sahara passage. At this time they normally increase their body reserves to around 50% of the LBM, but c. 10% of the birds gain 100%, thus doubling their mass. The passage there peaks around 20 April and continues well into May. That the main take‐off northwards is directly from the Guinea savannahs is indicated by the very low numbers trapped in the Sahel during spring.     

Bio-Economics of Large-Scale Eradication of Feral Goats From Santiago Island,Galápagos

ABSTRACT Invasive mammals are premier drivers of extinction and ecosystem change, particularly on islands. In the 1960s, conservation practitioners started developing techniques to eradicate invasive mammal populations from islands. Larger and more biologically complex islands are being targeted for restoration worldwide. We conducted a feral goat (Capra hircus) eradication campaign on Santiago Island in the Galápagos archipelago, which was an unprecedented advance in the ability to reverse biodiversity impacts by invasive species. We removed >79,000 goats from Santiago Island (58,465 ha) in <4.5 years, at an approximate cost of US$6.1 million. An eradication ethic combined with a suite of techniques and technologies made eradication possible. A field-based Geographic Information System facilitated an adaptive management strategy, including adjustment and integration of hunting methods. Specialized ground hunting techniques with dogs removed most of the goat population. Aerial hunting by helicopter and Judas goat techniques were also critical. Mata Hari goats, sterilized female Judas goats induced into a long-term estrus, removed males from the remnant feral population at an elevated rate, which likely decreased the length and cost of the eradication campaign. The last 1,000 goats cost US$2.0 million to remove; we spent an additional US$467,064 on monitoring to confirm eradication. Aerial hunting is cost-effective even in countries where labor is inexpensive. Local sociopolitical environments and best practices emerging from large-scale, fast-paced eradications should drive future strategies. For nonnative ungulate eradications, island size is arguably no longer the limiting factor. Future challenges will involve removing invasive mammals from large inhabited islands while increasing cost-effectiveness of removing low-density populations and confirming eradication. Those challenges will require leveraging technology and applying theory from other disciplines, along with conservation practitioners working alongside sociologists and educators.